Understanding the dynamics of an enclosed trawl demersal fishery in Patagonia (Argentina): A holistic approach combining multiple data sources

Abstract

Understanding the dynamics of a fishery is a key ingredient to successful fishery management. The objective of this study was to improve the understanding of the dynamics of the trawl demersal fishery that operates in San Matías Gulf (Patagonia, Argentina). This system offers an opportunity to explore different issues of fishery dynamics and management because it is a simple model with a few well-characterised active vessels and a stock of Argentine hake (Merluccius hubbsi) that seems to have been well preserved since the beginning of the fishery in 1970. This study combined different sources of information to analyse the seasonality of landings, the link between catch and landing profiles, and the association between sea surface temperature and the spatio-temporal variability in catch profiles. The monthly species composition of the catch fell into three fishing seasons, each with a distinct landing profile. During warm months, M. hubbsi dominated the catch, and bottom trawl activity was concentrated in a thermal frontal zone. In winter, the fishing activity was more disbursed over the surface of the gulf, and yields were minimal. From August to October, the landings increased rapidly due to the catch of Seriolella porosa, and the distribution of the fishing effort was partially concentrated in the northeastern area of the gulf. The seasonal pattern observed would be related to the resource availability and the commercial opportunities. These factors were significant in determining what, when, and where to fish in the trawl demersal fishery of San Matías Gulf.